1. Field of the Invention
This invention generally relates to the field of video processing, and, in particular, certain embodiments relate to a method and computer-readable medium for detecting flesh-tone pixels in pictures, images, and videos.
2. Description of the Prior Art
There are two common methods for detecting flesh-tone pixels in pictures, images, and videos. According to a first method, described for example in the YCbCr domain, if the Cb value of a pixel is between threshold—1 and threshold—2 (i.e., threshold—1<Cb<threshold—2), and the Cr value of the pixel is between threshold—3 and threshold—4 (i.e., threshold—3<Cr<threshold—4), the pixel is determined to be a flesh-tone, wherein the thresholds are predetermined by a user. However, since this method defines a rectangular region in the color space rather than an oval-shaped region, non-flesh-tone pixels can be included. Thus, this method may not accurately distinguish between flesh-tone pixels and non-flesh-tone pixels.
According to another method of detecting flesh-tone pixels in the YIQ domain, if the I value of a pixel is between threshold—5 and threshold—6 (i.e., threshold—5<I<threshold—6), and the Q value of the pixel is between threshold—7 and threshold—8 (i.e., threshold—7<Q<threshold—8), the pixel is determined to be a flesh-tone, wherein the thresholds are predetermined by a user. However, two color space conversions, such as from YCbCr to YIQ and from YIQ back to YCbCr, are required for this method, one before the determining process and one afterwards. Thus, this method complicates the procedure by adding two color space conversion operations.
Thus, the well known methods for detecting flesh-tone pixels are either inaccurate or too complicated. In view of the drawbacks mentioned above, there is a need for a new and improved method for detecting flesh-tone pixels.